Field of the Invention
The present invention relates to a liquid crystal display (LCD) device in which pixels adjacent to each other in a vertical direction, i.e., up and down within one gate line, are arranged in a display area to share a gate line and an auto probe test pattern is arranged in a non-display area. The present invention also relates to a method for testing the pixels of the LCD device.
Discussion of the Related Art
With the development of various portable electronic devices such as mobile terminals and notebook computers, the demands on flat panel display devices which are applicable to those devices are increasing.
Among the flat panel display devices, an LCD device is suitable for portable devices owing to various advantages such as being a highly-developed technology for mass production, easiness as a driving means, low power consumption, high picture quality, and providing a large-sized screen, and its application fields have been increased.
The LCD device displays images based on image signals by converting image signals, which are externally input, to data voltages, and controlling transmittance of light of a liquid crystal layer of a plurality of pixels.
The LCD device is fabricated by performing a process of forming various patterns including a thin film transistor (TFT) on a TFT array substrate (lower substrate), a process of forming various patterns including a color filter layer on a color filter array substrate, a liquid crystal cell process of bonding the TFT array substrate and the color filter array substrate to each other and injecting a liquid crystal between the TFT array substrate and the color filter array substrate, and a module process of connecting the TFT array substrate with a driving circuit.
After the TFT array substrate is fabricated, a process of testing an auto probe for detecting a line defect such as a shortage of lines formed on the substrate, a defect of the TFT, and a defect of a pixel pattern is performed.
A test pattern for an auto probe test is arranged in a non-display area of a liquid crystal panel. A shorting bar is used as the test pattern for an auto probe test, and a driving signal is applied to the gate and data lines through the shorting bar, whereby it is tested whether the lines and pixels on the TFT array substrate have been formed correctly.
FIG. 1 briefly illustrates an LCD device on which an auto probe test pattern is arranged in accordance with the related art. A TFT array substrate of a liquid crystal panel is shown in FIG. 1.
Referring to FIG. 1, the TFT array substrate of the LCD device according to the related art includes a display area A/A and a non-display area N/A.
In the display area A/A, a plurality of gate lines 12 and a plurality of data lines 14 are arranged to cross each other, and a plurality of pixels 16 are defined by crossing between the gate lines 12 and the data lines 14. A thin film transistor TFT and a storage capacitor Cst are arranged in each of the plurality of pixels 16.
A pixel structure of one gate/one data is shown in FIG. 1. Pixels 16 of red, green, and blue are arranged in the shape of a stripe. The pixels 16 arranged on one horizontal line are supplied with a scan signal from the same gate line 12, whereby their TFTs are switched. The pixels 16 of the same color, which are arranged on one vertical line, display images by receiving a data voltage from the same data line 14.
In the non-display area N/A, test patterns are arranged to test whether the plurality of gate lines 12, the plurality of data lines 14, and the plurality of pixels 16 have been formed correctly. A plurality of enable switches 20 and a plurality of data shorting bars 30 are arranged as the test patterns. The plurality of enable switches 20 are connected to the plurality of data shorting bars 30 through a plurality of link lines 40, and are connected to the plurality of data lines 14 through a link line and a data pad (not shown).
Although FIG. 1 illustrates that three data shorting bars 30 are used, there is no limitation in the number of data shorting bars 30, and two or six data shorting bars may generally be arranged to perform the auto probe test.
If two data shorting bars 30 are used, the plurality of data lines 14 may be divided into even lines and odd lines, and the entire plurality of pixels 16 is divided in half, whereby the pixels are tested. If three data shorting bars 30 are arranged, the plurality of data lines 14 may be divided into data lines of red pixels, data lines of green pixels, and data lines of blue pixels, whereby the pixels are tested for each color.
In the LCD device according to the related art, the pixels 16 of red, green, and blue are arranged in the shape of a stripe, and the test patterns are arranged to be suitable for a structure of pixels of a general LCD device, wherein the pixels do not share the gate and data lines. The pixels 16 may be tested for each color of the pixels of red, green, and blue by using the three shorting bars 30.
Recently, although a pixel structure of two data/one gate, in which pixels adjacent to each other in a direction perpendicular to the extension direction of the gate lines 12, i.e. in a vertical direction or up and down, share a gate line, has been developed, a problem occurs in that an auto probe test cannot be performed for the pixel structure of two data/one gate by the test patterns shown in FIG. 1. That is, the arrangement structure of the pixels 16 and the test pattern for an auto probe test are not matched with each other, whereby the auto probe test cannot be performed normally.
The pixel structure, the test pattern, and the method for testing pixels, which are described as above, have been used by the inventor of this application to devise the present invention, or are technical information obtained during the procedure of devising the present invention. Therefore, the pixel structure, the test pattern, and the method for testing pixels, which are described as above, may not be regarded as the known art disclosed to the general public prior to a filing date of the present invention.